Field of the Invention
The present invention relates to a wiring core structure provided in a wiring region where a parasitic inductance is to be suppressed in a large current circuit, a high frequency circuit and the like, that is, a wiring region to be a parasitic-inductance suppression target.
Description of the Background Art
In a large current circuit and a high frequency circuit, it is necessary to reduce a wiring parasitic L (inductance). An inductance L of a wiring cable, an applied current I, and a magnetic flux ϕ generated around the wiring cable have a relationship of {L=ϕ/1}.
In other words, the wiring parasitic L is caused by the magnetic flux generated around a wire. As a countermeasure to be taken against the wiring parasitic L, conventionally, the wiring is shortened as greatly as possible. Alternatively, a method using a twisted wire, a parallel plate or the like is utilized to cancel the magnetic flux.
Moreover, in order to suppress the wiring parasitic L, Japanese Patent Application Laid-Open No. 2001-313216 or the like discloses a noise-current absorbing tool that surrounds an outer peripheral part of a wire to absorb a noise getting in/out of an electric wire through an external environment.
However, a wiring physically needs a length to some degree. Moreover, a magnetic flux cannot be perfectly cancelled by using a twisted wire or a parallel plate. For this reason, a large current circuit or a high frequency circuit still has a problem of the wiring parasitic L. In addition, a conventional noise current absorber has a disadvantage in that the problem of the wiring parasitic L cannot be solved sufficiently.